Regulatory Assets and Liabilities (Textual) (Details) - SCE	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Regulatory assets, energy derivatives, low range of contract expiration (in years)	2 years
Regulatory assets, energy derivatives, high range of contract expiration (in years)	3 years
Regulatory assets related to deferred income taxes, recovery period, low range (in years)	1 year
Regulatory assets related to deferred income taxes, recovery period, high range (in years)	60 years
Low end of the range of remaining original amortization (in years)	10 years
High end of the range of remaining original amortization (in years)	40 years
Unamortized investments, net of accumulated amortization
Regulatory Assets [Line Items]
Return rate earned on assets included in rate base (as a percent)	7.68%	7.61%